Cinematographic screen



J. M. OGILVIE. CINEMATOGRAPHIC SCREEN. APPLICATION FILED AUG.22,1921.

stares- UINEMATOGBAPHIC SCREEN.

Specification of Letters Patent. 'Patgntd A 15 1922 Application filed August 22, 1921. Serial No. 494,358.

To all whom it my concern.-

Be it known that I, JULIAN MAOARTNEY OGILVIE, a subject of the King of England, residing at 68 Warwick Gardens, Earls Court, London, S. W., England, have invented certain new and useful improvements in cinematographic Screens (for which I have filed applications in England Aug .l6, 1920, Sept. 9, 1920, and May 17, 1921), of which the following is a specification.

This invention relates to screens for use in connection with cinematograph lanterns and like projection apparatus, of the kind having a metallic surface formed of powdered aluminium silver, bronze, or the like.

The object of the invention is to make such screens capable of producing a colour effect instead of the usual black and white efiect produced by the present screens of this type. Another object of the invention is to reduce as far as possible the shadow efiect which is rather pronounced with metallic or metallized screens when viewed from acute angles and to obtain an even diffusion of light at all angles of observation.

As far as the colour eifect is concerned the main feature of the invention consists in the use of a coloured background on to which the metallic powder is dusted or otherwise applied. Whilst any colours except black and white may be used, the colours preferably used are orange, or red, as being most suitable for general use. Green and blue backgrounds may be suitable for reproduction of wooded and like scenery and of sea-scapes.

Whilst the metallized surface of the screen has generally the efi'ect of reflecting the light and of producing a very clear reproduction of fine. detail, the coloured backound has the effect of giving a certain tone to the picture.

For reducing the shadow efiect and for matting the brilliant metallic surface barium sulphate is used as a final coating, which is spread on to or otherwise applied to the metallic coating. The barium sulphate may also be mixed with the metallic powder. a g

The coloured background for the metallic surface may be produced in any suitable manner, but it is preferred to prepare this background in such amanner as to enable the metallic surface to be formed thereon in the usual manner. In the accompanying drawing, Figure 1 1s a View of a port1on of a screen with parts of the coatings broken away.

Figure 2 is a sectional view therethrough. A screen embodying the features of the invention may be prepared in the following manner. A canvas or cotton fabric 1 in one seamless sheet is prepared in the usual way for painting. @ne or more coats of paint containing each white lead, red lead (or orange powder'iir other colouring matter), genuinelinseed oil and liquid driers, are then applied either by means of a brush or of a hand-spraying machine. If handpainting is used the surface should be carefully stip-pled. A final coat is, then applied which contains, in addition to the above mentioned ingredients, heavy stand 011. metallic powder 2, for instance alumimumlpdwder, is then thrown by hand upon the final coating, which should be in a suitable condition, i. e., nearly dry, but should have sufficient tackiness to hold the powder. The metallic powder is ently brushed all over the surface and. is nally, after a suitable interval, brushed ofi. The

powder may, of course, be applied in any other suitable manner, for instance, it may be sprayed on. The sheet is then sprayed one or more times with a mixture 3 of highly refined barium sulphate and glue diss0 ved in water. barium sul hate on to the aluminium, the barium su phate may be mixed with the aluminium.

The combination of a coloured background with a metallic surface consisting of powdered metal is the mainfeature of the invention, the object of the coloured background being to soften the hard effect produced by the metallic surface and to give a definite tone to the picture.

' I claim-- 1. A cinematographic screen com rising a colored background, a metallic sur ace of powdered aluminum, and an outer coating of barium sulphate.

2. A cinematographic screen comprising a red background, a metallic surface of powdered aluminum, and an outer coating of barium sulphate.

3. A cinematographic screen comprising a sheet of fabric, a plurality of coats of Instead of spraying the the metallic surface, substantially as de- 10 scribed.

lln testimon whereof he has hereunto set his hand in t e presence of two witnesses.

JULIAN MACARTNEY OGILVIE. Witnesses:

S. SoKAL,

I. McGIBBoN. 

